Machine-type communication (MTC) in cellular communication networks is increasingly gaining attention. Connected sensors, alarms, remote control devices etc. can in a cellular communication network co-exist with more conventional communication devices, such as mobile phones or wireless wide area network devices. Devices for MTC generally have different demands than the conventional communication devices due to their normally modest bit rate demands and sparse communication. On the other hand, MTC devices in many cases have strict demands on low power consumption.
A paging channel (PCH) is a downlink transport channel. The PCH is transmitted over the entire cell. The transmission of the PCH is associated with the transmission of physical-layer generated paging indicators, to support efficient sleep-mode procedures.
The communication device may use Discontinuous Reception (DRX) in idle mode in order to reduce power consumption. When DRX is used the communication device needs only to monitor one page indicator in one paging occasion per DRX cycle.
Paging procedure is used to transmit paging information to selected communication devices in idle mode using the paging control channel (PCCH). Upper layers in the network may request paging to establish a signaling connection, for example. The network may initiate paging for communication devices to trigger a cell update procedure. In addition, the network may initiate paging for communication devices in idle mode to trigger reading of updated system information.
Cellular communication systems, such as GPRS, WCDMA and LTE, are implicitly designed for services having unknown and/or irregular transmission/reception patterns. That is, in conventional communication it is assumed that the time when next call or packet transmission will occur is unknown. To provide low latency in the system, paging intervals are rather short. For example, the longest DRX cycle for LTE and WCDMA/HS is 2.56 seconds.
A transceiver of a MTC device employing DRX, but which may actually only be supposed to very occasionally receive and/or transmit data, e.g., once every 15 minutes, every hour or every day, depending on the application of the MTC device, will be spending most of its energy consumption on listening to paging signals, even though DRX is employed. It is therefore a desire to further reduce energy consumption for transceivers working in such conditions.